Railway traffic controlling apparatus



y 7,1935. I E. M. ALLEN 2 000,871

RAILWAY TRAFFIC CONTROLLING APPARATUS File May 12, 1954 INVENTOIR EarlMAllen y MUS/Zulu.

HIS ATTORNEY Patented May 7, 1935 arl M. Allen Swis'svale, Pa., assignorto'.The Union Switch & Signal Company, Swissvale.

Pa., a corporation of Pennsylvania I Application May 12, 1934, Saar Nb.725,313 21 Claims. (01. 246-41 My invention relates to railway traflic,controlling apparatus, andparticularlyto apparatus of the type involvinga railway switch which is controlledjointly by an operator :locatedtataremote point and by traffic conditions in the vicinity of the switch. r

More particularly, my present invention relates toapparatus of thischaracter involving approach locking means which in normal operationbecomes effective'to lock the switch whilea trainis approaching, but isreleased when the train enters the track section in which the switch islocated.

One feature of my, invention is the provision,'in apparatus of thischaracter, of ,novel and improved means for preventing improper releaseof the approach locking means inthe. event of momentary failure of thesource of track circuit cur.- rent for the section of track in which theswitch is located while such section is unoccupied; I r

I will describe one form of apparatusembodying my invention, and willthen pointout the novel features thereof in claims; I z

In the accompanying drawing, Fig. 1 is aIdiagrammatic view showing aportionof one form of apparatusembodying ,myinvention. Fig. 2 is adiagrammatic view showing certain circuits for the control of relayM inFig.1.. -Simi1ar reference characters refer tosf ilar parts in each ofthe views. V. V

Referring first to Fi 1,.the reference j-charac ters l and I designatethe track rails of a stretch of main track- E, which rails are dividedby insulated joints 2 to form a. main section X Y'and anapproachsection"WfX. The main section X.Y contains a switch A leading into aside track C. Trafiic moving toward the right through the main sectionX-,-Y is governed by'two signals SA and SB, which signals are.controlled in part by traflic conditions in the main section 'XT-Y andwill usually also be controlled fromaia. remote point, such as aninterlocking tower-or a des-;

patchers ofice. The control of these signals forms no part of my presentinvention, and,fconsequently, the controlling circuits are omitted fromthe drawing. The switch A is'provided with an operating mechanism D,which is also con-, trolled in part from a remote point, usually thesame point from j which the signals are controlled, through the mediumof circuits which are represented in the drawing bythereferenc'e'character G. Associated with the switch A is the usualapproach locking relay. M, having a front contact 8 included in theoperating circuits for the switch mechanism D, sothat the, switch cannotbe moved.

throughthe medium of its operating circuits G unless this relay isenergized. C g

The main section X--Y is provided with a track] circuit comprising asource of current, such as a battery 3 connectedacrossthe rails at oneend 15 of the section, and aprimarytrack relay P which g is'at timesconnectedacross therails at;the ot her end of. the section. This sectionis provided with a second track-circuit including asource .ofcur-u rent,such asabattery -1 and a slowreleasing sec .0 ondary track relay S,which elements are attimes connected in series across the railsiofthesection. The primaryirelay P is provided .Wlthfa pick-'up circuitwhichpasses from the upperrail I, through I the winding of relay P, and afront contacti of the secondary relaySto the lower rail 1%. Itfol lowsthat this circuitisclosed only when contact .6 on relay S is closed.Relay. B is also provided with a holding circuit, which passes, fromthe,-

upper rail I, through thewinding of relay,-P,. a '20.

front contact 4, of relay P, and aresistanc'e 15 to .the lower rail. IItfollows that this holding circuit is closed only whenrelay P isclosed. ,When relay P isr'eleased, battery landthe winding of relay Sare connected across the rails of section 25 Xf-Y,.through backc'ontact5 of relay'P, but when relay Pris ,closedflthis .pathjis, ofcourse,ope'n at contacti- When this .path is closed,relay Swill i beenergized when and only when the path is'comE pleted bythe wheels andaxles of a train: in sectionX Y.' .Q. 1. 1. a Q The appr0ach.'sectionW-X is provided with a. track circuit ofthe'usual type including asource ofcurrent 3 andatrack relayT, j g M 7 Referring now to Fig. 2,.the approach locking relay 1M is provided with an energizingcircuitwhich passes fromterminal B of a suitable source of current,through a contact SAawhich is closed only when signal SA indicates stop,a contact SBIO which is "closed only when signalSB indicates stop,jfront" contact TH offthe approach track'relayiTgand the winding ofrelay M to terminal O of. the same sourcej'of current. circuit isprovided with a shunt: around contact TI l which includes a back contactP12 of the primary relayP, and a front contact SI3 of the secondaryrelay 5. The circuitfor relay M is providedwith a second shuntaroundc'ontact'Tll ,rwhich second shunt includes a normally open contactof a manually operable time'element device Q. The circuit 9 V for relayM is provided with athirdshuntaround contact TH, whichthirdshuntincludes front contact ll of relay M; I 5

When switch A is in'the normalposition, signals SA andSB arezboth atstop, and .no trains contact SA9, so that relay M will become deener-vgized, and this will prevent the operator from operating switch A. If,when there is no train in the approach section W-X, the operatorreturns.

signal SA to the stop position, relay M will again become energized sothat the operator will be free to operate switch A. If, however, thesection W-X is occupied by a train, the return of the signal SA to itsstopposition not cause relay M to become energized'bec'ause the maincircuit for this relay will then be open at contact TI 1 of track relay'1. Under these conditions relay M can be energized only by operation ofthe slow-acting device Q.

I will now assume that signal SA has been cleared and that a trainmoving toward the right passes through the stretch of main track shownin Fig. l. When-the trainenters sectionX-Y, it will de-energize theprimary relay P, thereby closing at back contact 5 the path bywhichbattery l and secondary relay S are connected across the rails. Relay Swill then become energized, because itscircuit will be completed throughthe wheels and axles of the train. Signal SA will be returnedto the stopposition by virtue of the usual control of this signal by relay P. Apick-up icircuitiorrelay M will then be closed through contacts SAS andSBlii, back contact P i 2 of relay P, and front contact S13 of relay S,so that relay M will again become energized. When the train leavessection X-Y, relay'S will become de-energized because thetrain shunt isremoved from the rails of this section, but due to the slow-releasingcharacteristic of this relay its contact 6 will remain closed longenough for relay P to become energizedby battery 3 located at Y end oftrack section X-Y; Relay M will remain energized, so that the operatormay now reverse the switch A if he caresto d0-so.

i l I The operation of the apparatus when switch A is reversed andsignal SB (is clear will be apparent from the foregoing withoutdetailedexplana tion.

One important feature of my invention lies in the fact that amomentaryinterruption of the supply .of track circuit current for the mainsection X-Y, while this sectionis unoccupied and section WX is occupied,cannot result in improper energization of relay M, because under theseconditions relay S would remain de-ener- .gized due to the fact thatthere is no train in section X--Y to complete its circuit.

Another importantffeature of my invention lies in the fact thata'momentary interruption of the supply of track circuit current forthemainsection X- Y which might be caused by any number of reasons, suchfoiiht'ince "as malicious intent or a broken rail, will cause relay P toopen then a removal of the interrupting cause, such as the broken endsof a rail again making mechanical contact, cannot again energize relay'Puntil the cause of interruption has been ascertained and relayP has beenenergized by a mechanical con tact across-rails I and 1 or local'energization,

.nlthough -I have herein shown and described only one form of apparatusembodying my invention, -'is'1mderstood that various changes andmodifications may be inade therein within'the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section of railway track containing a switch, asource of track circuit current connected across the rails of saidsection, a primary track relay and a secondary track relay, a pick-upcircuit for said primary relay connected across the rails of saidsection and including a front contact of said secondary relay, a holdingcircuit for said primary relay connected across the rails of saidsection and including a front contact of the primary relay, means forconnect ing said secondary relay across the rails of said sectionthrough aback contact of said primary relay and an auxiliary source ofcurrent, and means for controlling said switch by said relays.

2 In combination, a section of railway track containing a switch, asource of track circuit current connected across the rails of saidsection, a primary track relay and a secondary track relay, a pick-upcircuit for said primary relay connected J across the rails of saidsection and including a front contact of said secondary relay, i

a holding circuit for said primary relay connected across the rails ofsaid section and including a front'contact of the primary relay, meansfor connecting said secondary relay across the rails of said sectionthrough a back contact of said primary relay and-an auxiliary source ofcurrent, a locking relay for controlling said switch, and a pick-upcircuit for said locking relay including in series a back contact ofsaid primary relay and a front contact of said secondary relay. 3. Incombination, a section of railway track containing a switch, a trackcircuit for said section including a source of current connected acrossthe rails and a primary track relay normally connected across the railsthrough its own front contact, a secondary relay connected across therails of said section through an auxiliary source of current and abackcontact of said primary relay, apick-up circuit for said primary relayconnected across the rails of said section and including a front contactof said secondary relay, and means for controlling-said switch by saidrelays. V 4. In combination, a section of-railwa'y track containing aswitch -a track circuit for said sec- -tion including a source ofcurrent connected across the rails and a primary track relay normallyconnected across the railsthrough its 'own front contact, 'a Secondaryrelay connected across the rails of said section through an auxiliarysource of current and a back contact of said primary relay, a pick-upcircuit for said primary relay connected across/the rails of saidsection and including a front contact of saidsecondary relay, a lockingrelay for controlling said switch,

and a pick-up circuit for saidlocking relay including in series a backcontact of -said primary relay and a frontcontact of said secondaryrelay. 5. In combination, a section of railway track containinga-switch, a track circuit for said section including a source of currentand avprirnary track relay each connectedacross the rails, a secondarytrack relay and an auxiliary source of current connected in seriesacross the rails of said section, and means "i or controlling saidswitch by said relays.

6."In combination, a section of railway track containing a switch, -'atrack-circuit for said section including a'sourc'e of current and aprimary trackrelay each connected across the rails, a

7. In combinatiomra section of railwaytrack containinga switch, a sourceof track circuit cur-. rent connectedacross the rails of said-section, aprimary track relayand a secondary track relay,

means for-normally connecting said primary relay ac'ros'sthe rails ofsaid I section 'through its own front contact, auxiliary means forconnecting-said primary relay across the rails of saidsection when andonly=when said secondary relayis closed, means for connecting saidsecondaryrelay'end an auxiliary source of currentjin series acr'oss th'erails of said section when and only when said primary relay isopen,and-a controlling circuit for said switch including in series a backcontact of said primary relay and a front contact of said secondaryrelay.

8 In combination, a section of railway track containing a switch, atrack circuit for saidlsection including a source of current and aprimary track relay each connected across the rails, a sec-, ondarytrack relay and an auxiliary source of' current connected in seriesacross the rails of said section, and a controlling circuit for saidswitch including in series a back contact of said primary relay and afront contact'of said secondary relay.

9. In combination, a section of railway track containing a switch, atrack circuit for said section including a normally energized relaywhich releases when a train enters the section, a second track circuitfor said section including anormally deenergized relay which becomes.energized when a train enters the section and remains energized as longas the train remains in the section, and a controlling circuit for saidswitch including in series a back contact of said first relay and afront contact of said second relay. 7 a

10. In combination, a section of railway track containing a switch, atrack circuit for said-section including a normally energized relaywhich releases when a train enters the section, a second track circuitfor said section including a normally deenergized relay which becomesenergized when a train enters the section and remains energized as longas the train'remains in the section, and means for controlling saidswitch jointly by said two relays.

11. In combination, a section of railway track, a track circuit for saidsection including a normally energized relay which releases when a trainenters the section, a second track circuit for said section including anormally deenergized relay which becomes energized when a train en-'ters the section and remains energized "as long as the train remains inthe section, anda trafiic governing device associated with said sectionand controlled jointly by said two relays.

- 12. In combination,a section of railway track, a track circuit forsaidsection including a normally energized relay which releases when atrain enters the section, a second track circuit for said sectionincluding a normally deenergized relay which becomes energizedwhen atrain enters the section and remains energizedas long as the trainremains in the section, a traflic governing device associated with saidsection,fand a controlling circuit for said device including in frontcontact of said second relay.

front contact of said relay 3 series ai'back contact-of said firstrelay'and a 13. In combination, a section vof railway track containing:a switch, a contactarranged toibe closed-by a train occupying saidsection, a. relay and asource of current, :means elfectivewhen saidcontact is closed for connecting said relay- Y and said source in seriesacross tlie rails of said section, locking means for at times preventingoperation of said switch; andlmeans-includinga for releasing saidlocking'means. 1 14. Incombination with a section'of railway track and asource of current-connected across the rails of, said section, atrackrelay and. an auxiliary relaypa pickup circuit for "said trackrelay connected across the rails Y of the section the rails of thesection, atrack relay and an aux-' and including 'fafront contactof theauxiliary o =relay, a holdingcircuit for said track relay con iliaryrelay, apickup circuit for saidtrack relay I connected across therailsof the section and including a'front contact of the auxiliary relay, a

,holding circuit for said track relay connected across the rails or thesection and including a resistor adapted to be short circuited by saidfront contact, and means for energizing said auxiliaryrelay when andonly when the armature of the track relay is down.-

l6. Inv combination with a section of. railway track and a source ofcurrent connected across the rails of: the section, a track relay, aholding circuit for said relay connectedacross the rails of the sectionand including a resistor in series withthe operating winding of therel'ay,a circuit controlling contact shunting around said. re-

sistor and normally open, a pickup circuit for said track relayconnected across therails of the sec:

tion and including said contact, electromagnetic means effective whenenergized toclose said contact, and means to energize theelectromagnetic means rendered active in response to ,a train enteringthe section.

17. In combination with a section of. railway track and asource ofcurrent connected across the rails of said section, a tracklrelay, andan auxiliary relay, a pickup circuit-for said track relay connectedacross the rails of the section and including a front contact of theauxiliary relay, a holding circuit for said track relay connected acrossthe railsof the section and including a resistor connected so as to beshunted by said front contact, another source of current, and a circuiteffectiveto energize said auxiliary relay including said other source ofcurrent and a back contact of the track relay.

18..In combination with a-section of, railway I track and a source ofcurrent connected across the rails of said section, a track relay and anauxiliaryrelay, a pickup circuit for said track relay connected acrossthe rails of the section "and including a front contact of the auxiliary-relay,j.a holding circuit for said track relay connected across therails of the section and including a resistorand a front contact .of thetrack relay, and an energizing circuitfor the auxiliary relay connectedacross, the rails of the section,

and, including a back contact of the track relay.

19. In combination with a section of railway track and a source ofcurrent connected across the rails of said section, a track relay and anauxiliary relay, a pickup circuit for said track relay connected acrossthe :rails of the section and including a front contact of the auxiliaryrelay, a

holding circuit for said track relay connected across the rails of thesection and including a resistor adapted to be short circuited by saidfront contact, another source of current, and an energizing-circuit forsaid auxiliary relay connected across the rails of the section andincluding a back contact of the track relay as well as said other sourceof current, whereby said energizing circuit ,will become effective whenand only, when saidsection is occupied by a train.

20. In combination with a sectionofrailway track and a source of currentconnected across;

the rails of ,said section, a track relay and an auxiliary relay, apickup circuit for said track relay connected across the rails of thesection and including a front contact of the auxiliary relay, a holdingcircuit for said track relay connected across therails of the sectionand including a resistor adapted to be short circuited by said frontcontact, another source of'current, and

a circuit for energizing said auxiliary relay from said other source ofcurrent when and only when said section is occupied by a train.

,21. In combination, a section of railway track, a track-circuit forsaid section including a first source of current and a normallyenergized relay which releases when a train enters the section, a secondtrack circuit for said section including a second source of current anda normally deenergized, relay which becomes energized when a trainenters said section and remains energized aslong as the train remains inthe section, and a traffic governing device associated with said sectionand controlled jointly by said'two relays.

EARL M. ALLEN.

